This invention relates to control systems for motorized wheelchairs or personal transport vehicles (PTV), and in particular to customizing mechanisms for such wheelchairs.
Motorized wheelchairs come in many different types, depending upon the abilities of the person expected to use the wheelchair. Some wheelchairs have stair climbing capabilities and other characteristics. A joystick is used as a typical input mechanism to control both the speed and direction of the wheelchair. However, some wheelchair users are unable to operate a joystick because of their disability. Other input mechanisms include voice control, head gear responsive to movements of the head, and an air pressure sensor responsive to blowing and sucking through a straw. Depending upon the type of input used, the input circuitry must be modified to handle input signals and provide the appropriate drive signals to the wheelchair motors in response.
In addition, even for a specific type of input, such as a joystick, there are variations among users. For instance, some users can operate a joystick only marginally since their hand may be constantly shaking. Thus, special filtering circuitry can be included to cancel out the affects of such shaking. In addition, a user may be able to only provide jerky movements, which would result in very rapid acceleration or deceleration unless modified. These modifications can be done by using different circuitry or providing switches as inputs to a processor in the back of the wheelchair which can be configured in accordance with a particular user's needs. Obviously, the use of such switches makes the circuitry complicated and requires a technician to configure the wheelchair for the particular user, adding to the costs. U.S. Pat. No. 4,634,941, for example, discloses in Col. 8 the use of variable resistances to control acceleration and deceleration.
Some wheelchairs are used in a multiple-user environment, such as a convalescent home, where the wheelchair must be reconfigured each time a new user is provided with the wheelchair. In addition, access to the wheelchair must be controlled where there is danger that a particular user may be injured in a wheelchair not adapted to that user's particular disabilities.